Determination of chloramphenicol in muscle using a particle beam interface for combining liquid chromatography with negative-ion chemical ionization mass spectrometry

Determination of chloramphenicol residues in shrimps by liquid chromatography-mass spectrometry

A liquid chromatographic method with mass spectrometric detection and identification (LC-MS) is presented for the determination of chloramphenicol (CAP) in shrimp tissues. Homogenized shrimp samples were extracted with phosphate buffer (pH 7.0). Clean-up was carried out on a C(18) SPE cartridge. Chloramphenicol was determined by LC-MS-ESI in negative mode. The column used was a Symmetry Shield with a mixture of acetonitrile-water (25:75) as mobile phase. Shrimp samples were fortified at CAP levels between 0.2 and 50 ng g(-1) with 5D-CAP as internal standard. At these levels, accuracies lay between 101 and 110% and between-day reproducibilities were lower than 7.1%, expressed as the variation coefficient of the mean. Limit of decision (CCalpha) was 0.02 ng g(-1). Limit of quantitation (LOQ) was 0.2 ng g(-1).

Matrix solid-phase dispersion extraction and gas chromatographic determination of chloramphenicol in muscle tissue

A method based on matrix solid-phase dispersion (MSPD) was developed for the gas chromatographic (GC) determination of chloramphenicol (CAP) residues in animal muscle tissue. Muscle tissue was blended with octadecylsilyl-derivatized silica (C(18)). A column made from the C(18)/muscle tissue matrix was washed with n-hexane and acetonitrile/water (5 + 95), after which CAP was eluted with acetonitrile/water (50 + 50) and partitioned into ethyl acetate. The final extract was evaporated, and a trimethylsilyl derivative of CAP was prepared with Sylon HTP and detected by GC with an electron capture detector (ECD) and a mass spectrometer. For quantitation, the internal standard used was the meta isomer of CAP (m-CAP) for GC-ECD. Muscle tissue samples were fortified at three concentration levels. At 5, 10, and 15 microg/kg levels the respective mean recoveries were 93, 96, and 98%, and the repeatabilities were 13, 11, and 3%. The detection and quantitation limits with ECD were 1.6 and 4.0 microg/kg, respectively. No statistically significant difference was observed in the efficiency of CAP extraction from muscle tissue of various animals (bovine, porcine, and poultry) by the MSPD technique.

Liquid chromatographic-mass spectrometric methods for analyzing antibiotic and antibacterial agents in animal food products

Public health agencies in many countries rely on detection by mass spectrometry for unambiguous identification of residues of antibiotic and antibacterial agents in animal food products for human consumption. The introduction of relatively inexpensive and robust LC-MS systems has given a strong impulse to develop determinative and confirmatory methods for the above medicines in foodstuffs. This impulse has been also dictated by thermal instability and lack of volatility of many antibiotics and antibacterials that makes the GC-MS technique of difficult application. Analytical methods developed for analyzing components of the major classes of the medicines mentioned above are here reviewed. The discussion is focused on both sample treatment and final LC-MS analysis.

Analysis of antibiotics by liquid chromatography-mass spectrometry

The current status of the application of LC-MS in the analysis of antibiotic and antibacterial compounds is reviewed. The main application area of LC-MS in this field is the confirmation of identity in animal food products for human consumption at maximum residue levels, set by the regulatory authorities. LC-MS is found to play an important role in the determination and confirmation of sulphonamides, beta-lactam antibiotics, (fluoro) quinolone antibiotics, as well as various other groups including aminoglycosides, chloramphenicol, ionophore antibiotics, 5-nitrofuran derived compounds and macrolide antibiotics. Currently available data on these compound classes are reviewed, with special emphasis on important aspects especially relevant to LC-MS and on the mass spectral information obtained.

Use of liquid chromatography-mass spectrometry in the analysis of residues of antibiotics in meat and milk

The advent of affordable LC-MS systems has led to a massive increase in a number of publications describing quantitative methods for the analysis and confirmation of veterinary drug residues. The lack of volatility and thermal instability of many antibiotics makes LC-MS the method of choice for their analysis. In the review, analytical methods for the determination of residues of each of the major classes of antibiotics are presented.

Applications of liquid chromatography-mass spectrometry interfacing systems in food analysis: pesticide, drug and toxic substance residues

This paper reviews applications of different LC-MS techniques for the determination of xenobiotic substances in foods. Specific examples of contaminants discussed are pesticides, herbicides, insecticides and drugs; concerning toxic substances, mycotoxins, phycotoxins, cyanobacterial toxins, mutagenic and heterocyclic amines and beta-carbolines, arsenic, tin and inorganic halogen compounds, packaging materials and various epoxy resins are considered. Advantages and limitations are outlined for the different LC-MS interfacing systems (particle beam, thermospray, atmospheric pressure ionization with electrospray, ionspray and heated pneumatic nebulizer). The impact of developments in instrumental analysis on methodology and the limitations of the various LC-MS methods are discussed. Further, the coupling of LC with element-selective detection systems such as inductively coupled plasma mass spectrometry is discussed, with emphasis on speciation of trace toxic elements in foods.

Optimization of the analytical performance of the magnetic sector mass spectrometer for the identification of residual chloramphenicol in shrimp

Chemical noise limits mass spectrometric detection of chloramphenicol (CAP) with electron capture ionization at low resolution, and makes CAP identification at concentrations of 5 parts per billion (ppb) difficult. Increasing the resolution from 1000 to 3500, however, was sufficient to separate the analyte signals from the noise signals, and resulted in a 100 times higher analytical sensitivity. The introduction of sweep gas in the ion source decreased the scattering of the quantitative results on average by a factor of 7, and thereby improved the precision of the analyses to an acceptable level (CV < 10%). Under such conditions, CAP residues of 1.5 and 2.1 ppb in shrimp as determined by electron capture gas chromatography/mass spectrometry can readily be identified by monitoring four diagnostic ions.